JONATHAN THOMAS is a major Six Nations doubt after damaging a shoulder joint.

The in-form blindside flanker is almost certain to miss the remainder of the Ospreys' Heineken Cup dogfight with Stade Francais and Sale Sharks.

The 23-year-old hurt his left shoulder during last weekend's stuttering 26-9 victory over Italian minnows Calvisano at the Liberty Stadium.

He went off six minutes from time with the injured arm in a makeshift sling and has been examined by a bone specialist.

Twenty-eight times capped Thomas was told he wouldn't need surgery but intense physiotherapy and could be out for four to six weeks.

It's a huge blow for the popular forward, who was in the Wales team that drew with Australia, was a substitute in the win over the Pacific Islanders, scored two tries when they beat Canada and lost to New Zealand during the autumn campaign.

Thomas (pictured) was appointed "line-out captain" by Wales coach Gareth Jenkins and they posted an improved success rate in that facet.

If Thomas is out for six weeks he'll have little time to prove his fitness before Wales' Six Nations opener with joint championship favourites Ireland at the Millennium Stadium on February 4.

His absence will be a significant loss for the Ospreys, who have three crunch Welsh Magners League derbies over the Christmas period and with the group stage of the Heineken reaching a dramatic climax.

They are a point behind leaders Stade in Pool Three and four in front of Sale with it all to play for.

Victories in their two remaining fixtures, against Stade in Swansea and at the Sharks, would give them a first appearance in the knockout stage of the European showcase.

Success for the Ospreys over Stade at the Liberty Stadium on January 14 wouldn't guarantee them a quarter-final passage - they will most certainly have to win at Sale to make sure of topping the group of death.

Sale can't win it unless they pick up bonus-point victories in Calvisano and against the Ospreys in the finale, and Stade fail to pick up five more points, which appears a formality given they face the Italians.

However, finishing on 20 points might be enough to see Sale go through as one of the two best runners-up from the pool stage.

Stade coach and former France captain Fabien Galthie was delighted the Paris aristocrats secured a potentially priceless bonus point against the Sharks - and warned of the challenge they face against the Welsh region.

"When you look at the group now, we can start thinking about it but Ospreys, in particular, are a very dangerous team with a lot of very good players," he said.

"That's why it was so important we got the bonus point at Sale. We have to make sure we get into the quarter-finals."

Welshman Lee Thomas, the former Blues outside-half or centre, kicked three penalties and Chris Bell added a drop-goal during Sale's 12-6 win over Stade at Edgeley Park.

"We will try to get five points in the next two games. We'll also see what happens when Stade Francais go away to Ospreys.

"I ask my players never to give up and we've won here. We'll fight until the last game.

"We are missing 12 to 13 players through injury so it makes things difficult but we dug in for the win and will keep on fighting."